quick_start

Quick Start

Let's start with deploying a simple workflow on a local instance of Llama Deploy. We recommend to use a virtual environment where you installed llama-deploy before running any Python code from this guide.

The src folder contains a workflow.py file defining a trivial workflow:

import asyncio
from llama_index.core.workflow import Workflow, StartEvent, StopEvent, step


class EchoWorkflow(Workflow):
    """A dummy workflow with only one step sending back the input given."""

    @step()
    async def run_step(self, ev: StartEvent) -> StopEvent:
        message = str(ev.get("message", ""))
        return StopEvent(result=f"Message received: {message}")

To begin, you can test that the workflow correctly runs locally:

$ python src/workflow.py
Message received: Hello!

To be able to run the workflow above within Llama Deploy, a deployment must be defined in YAML format. This is the code you'll find in the file quick_start.yml from the current folder, with comments to the relevant bits:

name: QuickStart

control-plane:
  port: 8000

default-service: echo_workflow

services:
  echo_workflow:
    name: Echo Workflow
    # We tell Llama Deploy where to look for our workflow
    source:
      # In this case, we instruct Llama Deploy to look in the local filesystem
      type: local
      # The path in the local filesystem where to look. This assumes there's an src folder in the
      # current working directory containing the file workflow.py we created previously
      name: ./src
    # This assumes the file workflow.py contains a variable called `echo_workflow` containing our workflow instance
    path: workflow:echo_workflow

The YAML code above defines the deployment that Llama Deploy will create and run as a service. As you can see, this deployment has a name, some configuration for the control plane and one service to wrap our workflow. The service will look for a Python variable named echo_workflow in a Python module named workflow and run the workflow.

At this point we have all we need to run this deployment. Ideally, we would have the API server already running somewhere in the cloud, but to get started let's start an instance locally. Run the following python script from a shell:

$ python -m llama_deploy.apiserver
INFO:     Started server process [10842]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://0.0.0.0:4501 (Press CTRL+C to quit)

From another shell, use the CLI, llamactl, to create the deployment:

$ llamactl deploy quick_start.yml
Deployment successful: QuickStart

Our workflow is now part of the QuickStart deployment and ready to serve requests! We can use llamactl to interact with this deployment:

$ llamactl run --deployment QuickStart --arg message 'Hello from my shell!'
Message received: Hello from my shell!

Run the API server with Docker

Llama Deploy comes with Docker images that can be used to run the API server without effort. In the previous example, if you have Docker installed, you can replace running the API server locally with python -m llama_deploy.apiserver with:

$ docker run -p 4501:4501 -v .:/opt/quickstart -w /opt/quickstart llamaindex/llama-deploy
INFO:     Started server process [1]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
INFO:     Uvicorn running on http://0.0.0.0:4501 (Press CTRL+C to quit)

The API server will be available at http://localhost:4501 on your host, so llamactl will work the same as if you run python -m llama_deploy.apiserver.